Prostate cancer is the second most common cancer in American men. Moreover, present treatment of recurrent prostate cancer is largely unsuccessful. The cancer stem cell concept holds that mutated undifferentiated cells drive tumorigenesis and that the lack of current cancer treatments to target these cells leads to recurrence. This laboratory proposes that stem cells exist in the prostate and that malignant transformation of these stem cells leads to cancer. The mouse will be used as a model for human prostate. While our ultimate aim is to identify putative prostate cancer stem cells, the current project is focused on first identifying the putative stem cells in normal prostate tissue. Experiments will focus on recovering prostate tissue from mice, then fixing, sectioning and staining this tissue with antibodies against a variety of stem cell markers. Prostate tissue will also be dissociated and flow cytometry will be utilized to separate cell populations expressing stem cell markers in an effort to characterize the stem cell properties of these cells.